day2: Write a basic unit test for part 1

2/navigator.hs

@@ -1,11 +1,12 @@
+import           Control.Exception (assert)
+
 main :: IO ()
 main = do
   instructions <- getContents
-  let
-    parsed = parseInstructions instructions
-    location = navigate parsed
-    solution1 = uncurry (*) location
-  print solution1
+  putStrLn (solution1 instructions)
+
+solution1 :: String -> String
+solution1 input = show (uncurry (*) (navigate (parseInstructions input)))
 
 parseInstructions :: String -> [(Int, Int)]
 parseInstructions instructions =
@@ -23,3 +24,18 @@ navigate instructions =
   where
     sumTuples :: (Int, Int) -> (Int, Int) -> (Int, Int)
     sumTuples (a, b) (c, d) = (a + c, b + d)
+
+-- Tests
+
+testInput1 :: String
+testInput1 = unlines [
+  "forward 5",
+  "down 5",
+  "forward 8",
+  "up 3",
+  "down 8",
+  "forward 2"
+  ]
+
+test1 :: String
+test1 = assert ((solution1 testInput1) == "150") "success"